FOR RICHER... AND RICHER

MUSK: His girlfriend of two years is Canadian musician Claire Boucher, who is 17 years his junior. She performs under the name of Grimes — and in May last year gave birth to a boy named X-AE-A-XII, or X for short. BEZOS: He was accused of cheating on his (now ex) wife MacKenzie with current girlfriend Lauren Sanchez, 51. Lauren was married to movie agent Patrick Whitesell and the pair were friends with Bezos and MacKenzie. After 18 months of dating, Lauren (right with Bezos) has been spotted with what looks like a knuckle-duster of an engagement ring. GATES: Bill has been devoted to wife Melinda, 56 (left), for nearly 30 years. The couple met when she started working for Microsoft as a product manager in 1987. They have three g grown-up p children.